From patchwork Mon Feb 26 20:21:39 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [4.15,02/64] arm64: mm: dont write garbage into TTBR1_EL1 register From: "gregkh@linuxfoundation.org" X-Patchwork-Id: 10243307 Message-Id: <20180226202153.550888076@linuxfoundation.org> To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Nicolas Dechesne , Greg Kroah-Hartman , Will Deacon , stable@vger.kernel.org, Ard Biesheuvel Date: Mon, 26 Feb 2018 21:21:39 +0100 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ard Biesheuvel Stable backport commit 173358a49173 ("arm64: kpti: Add ->enable callback to remap swapper using nG mappings") of upstream commit f992b4dfd58b did not survive the backporting process unscathed, and ends up writing garbage into the TTBR1_EL1 register, rather than pointing it to the zero page to disable translations. Fix that. Cc: #v4.14 Reported-by: Nicolas Dechesne Signed-off-by: Ard Biesheuvel Acked-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/mm/proc.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -155,7 +155,7 @@ ENDPROC(cpu_do_switch_mm) .macro __idmap_cpu_set_reserved_ttbr1, tmp1, tmp2 adrp \tmp1, empty_zero_page - msr ttbr1_el1, \tmp2 + msr ttbr1_el1, \tmp1 isb tlbi vmalle1 dsb nsh